"The Insomniac Playground" comes from my college days. When I would have my periodic bouts of stress-induced insomnia, I would go to the all-night computer lab on campus and (usually) surf the net or (rarely) work on a programming assignment.
One night/morning when I finally felt tired enough to sleep, I walked back to my dorm room and flopped into bed as my roommate was getting up. She asked, "Were you up all night again?".
Half in a coma, I answered, "Yeah. I was running around the insomniac playground". When I regained consciousness around lunch time, Steph asked me if I remembered what I said earlier (which I didn't, so I had to go with Steph's version of events <s>).
From then on, we both referred to the Internet as "The Insomniac Playground". I decided to use it as the title of my page out of a sense of nostalgia and because now when I can't sleep, I usually write or think about story ideas. See? I told you it was a fascinating anecdote... <g>